Motor-controller.



U. T. HENDERSON.

MOTOR CONTROLLER.

APPLICATION FILED APR. 23, 1909.

945,093. Patented Jan. 4, 1910.

UNllTED STATES EATENTET CLARK '1. HENDERSQN, OF MILWAUKEE, "WESGONSIN, ASSIGNOIR, T0 1'1 HAMMER MFG. 00., OF MILWAUKEE, VJXSCUNSIN, A SGEPGBATIGL G3? hEUTDR-fiGNTEQLLER.

To all whom it may concern."

Be it known that I, CLARK T. Hnnnnason, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in lllotonControllcrs, of which the following is a full, clear, eonelse, and exact description, reference being hadto the accompanying drawing, forming a part of this specification.

My invention. relates to improvements in controllers for electric motors.

More particularly it relates to controllers in which the startingresistance controlled by means of a plurality of independent switches, each switch being provided with. a throttling device for preventing closure thereof while there is an excessive flow of current through the motor. In my prior patent, No. 890,979, granted June 16, 1908,

l have disclosed a controller of this ype in which the winding of each of the throttling devices is connected in series with the nzotor armature and the resistance sections controlled by its own and succeeding resistance switches.

According to my present invention, instead of connecting the windings of the throttling devices in series with the sections of starting resistance, controlled by their corresponding resistance switches, 1 connect the same in parallel therewith. I also provide means whereby each of the throttling devices may be adjusted to respond under ditlerent predetermined conditions.

In order to more clearly set forth the characteristic features of my invention, l shall describe the system of control dire grammatically illustrated in the accompany-- ing drawing, which QIHbOdlES IHY invention in certain forms.

Of course, myinvention is susceptible of various modifications.

no system of control illustrated includes a main switch 1, resistance switches 2, 3, i and 5, and throttling switches 6, 7, 8 and 9, one for each of the resistance switches. The switches 1, 2,3, 4 and are provided with operating windings l 2, 3, l and 5, respectively. The switches2, 3, and 5, are arranged to control resistances R it, and K, respectively. These resistances are arranged in circuit with the motor, which is illustrated as provided with an armature A and series field winding F. The circuit Specification Letters Patent.

arrangement for the operating win the resistance switches is suhstantia same as that illu' 'ated in my former lhe resistance switches 2, 3 and a vided with auxiliary contacts 10, ll respectively, each of which is adapted to engage a stationary Contact to complete the circuit of the operat g winding oil the nextsection of starting resistance controlled b its corresponding r sistance switch. windings of the thro'ttlingswitches {i and i are shown as provided witl devices for connecting one terminal of each to its respoiuling resistance section at diii' re points, while the windings of the throttli switches 8 and 9 are shown as having Va able resistances 1.7 connected in series th with. 1 1e purpose of these zu'rangenicnts will he hereinafter set forth.

shall now briefly describe the operation of the system of control illustrated. Cur rent is supplied from main lines 20 and El through a main line switch The operation of the various switches is initially controlled by a switch 23, which, when closed, first completes a circuit from main line 20 by conductor 2% through the operating winding 1 of the main switch 1 by conductor :25 to conductor and thence to the negative line :21. Upon energization of the winding 1 the main switch 1 is closed, thereby conr pleting the motor circuit from. conductor Let through t..-e nrain switch 1 by conductor I." thence dividing'l through the operating wi' ding 6 o" 1e throttling switch and res. -ance sec on it", thence dividingly through each 0 e rcsi"'ance seclons l R and and wincngs of their correby t nductor ding .u go the negative line.

circuits may be so proportioned that the throttling switches will respond only when there is an excessive flow of current through the motor. Hence, should there be an excessive flow of current through the motor, when the main switch 1 is closed, the throttling device 6 would respond, thereby interrupting the circuit of the winding 2-. 0n the other hand, if the motor was able to ta re care of the in-rush of current upon the closure of the main switch 1, then the throttling device 6 would not respond and circuit would be completed from switch when fully closed, by conductor 30 through the throttling switch 6, thence through the winding 2? of the resistance switch 2 and conductors 25 and 26 to the negative line 21. The switch 2 would thereupon close, thereby short-circuiting the resistance section The resistance R would thus be removed from the motor circuit, and current would flow from the main switch through the resistance switch 2, thence dividingly through the remaining resistances and their corresponding throttling windings to the motor. Closure of the switch 2 causes the auxiliary contact 10 to engage its stationary contact, thereby completing the circuit of the winding 3 from main switch 1, auxiliary switch 10, conductor 31 to throttling switch 7 by conductor 32 through the winding 3, and thence by conductors '25 and 26 to the negative line. If, however, upon the removal of the resistance I from the motor circuit, there was an excessive flow of en"- rent through the motor, the throttling device would respond, thereby interrupting the circuit of the winding 3". This would occur before the winding 3 was sufficiently energized to close the switch 3, and consequently said switch would not be closed until normal conditions were restored and the throttling switch 7 had returned to closed position. Closure of the switch 3 short-circuits the resistance R and completes the circuit of the winding P of the switch 4, from auxiliary contact 11 by conductor 83 through switch 8, (it closed), by conductor 34 through the winding 4 to conductor 25. Of course, if the throttling switch 8 responded, the winding 4* would not be energizeduntil normal conditions were restored. Closure of the switch 4 short-circuits the resistance R and completes a circuit from auxiliary contact 12 by conductor 35 through the throttling switch 9 by conductor 36 through the winding 5 of the switch 5. The switch would thereupon close as soon as the relay switch returned to closed position, if the same had in the meantime responded to an excessive flow oi current. Upon closure of the switch 5 the motor cirthey would den tie-aces cui't is completed from main switch 1 by conductor 37 through switch 5 and thence through the motor. Each of the resistance switches not only short-circuits a portion of the starting resistance, but also short-circuits the winding of its corresponding throttling switch, thereby rendering the same inoperative.

I shall now describe the purpose of the members 16 for connecting one terminal of each of the throttling windings 6 and 7 to their respective resistance sections at different points. As previously pointed out, the amount of current flowing through each of the throttling windings depends upon the relative resistances of the two parallel circuits. It is obvious more current would flow through each of the throttling windings when connected in parallel to an entire section of resistance than when connected in parallel to only a portion thereof. Hence, it the members 16 were moved to the left e stance in shunt thereby decrees "rent therethrough. It An that this arrangement: net the throttling devices ent prode ermined ing the liow ct will, therefore be L t may be acoi the variable rev g in series with the throttling and. By increasing the amount tance in series with the throttiing win rings, the flow of current therethrough would be decreased, and vice versa. Both of these arrangements, it will be observed, enable me to adjust each of the throttling devices independently of the remainder.

Ct course, other means might be employed for adjusting the relay devices which would fall w thin the scope of my invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is-

1. In a controller for electric motors, in con'ibination, a resistance, an automatic switch for controlling said resistance, and

an electroresponsive throttling device, having its winding connected in parallel with a predetermined amount of said resistance, said throttling device being adapted to prevent the operation of said switch while there is an excessive flow of current through the motor 2. In a controller for electric motors, in combination, a resistance, an automatic switch for controlling said resistance, and an electro responsive throttling device having its winding connected in parallel with a predetermined amount of said resistance, said throttling device being adapted to prevent the opera tion of said switch while there is an excessive flow of current through the motor, and means for adjusting said throttling device to respond under different pre determined conditions.

3. In a controller for electric motors, in combination, a starting resistance, a plurality of automatically operated switches for gradually removing said starting resistance from circuit, and a plurality of clectrora sponsive throttling devices for arresting the successive operation of said switches upon an excessive flow of current through the motor, the controlling winding of each of said throttling devices being connected in parallel with a portion of said resistance.

a. In a controller for electric motors, in combination, a starting resistance, a plural ity of automatically operated switches for gradually removing said starting resistance t'rom circuit, a plurality of electroresponsive throttling devices for arresting the successive operation of said switches upon an excessive flow of current through the motor, the controlling winding of each of said throttling devices being connected in parallel with a portion of said resistance, and means for adjusting said throttling devices to respond under different predetermined conditions.

5. In a controller for electric motors, in combination, a plurality of successively operated resistance switches, a section of resistance controlled by each of said switches, a plurality of electroresponsive throttling devices, one for each of said switches, each of said throttling devices having its controlling winding connected in parallel with a predetermined amount of the resistance controlled by its corresponding switch and being adapted to prevent'the operation of its corresponding switch while there is an excessive flow of current through the motor.

6. In a controller for electric motors, in combination, a starting resistance, a plurality of automatically operated switches for gradually removing said starting resistance from circuit, a plurality of electroresponsive throttling devices for arresting the successive operation of said switches upon an excessive flow of current through the motor, the controlling winding of each of said throttling devices being connected in parallel with a portion of said resistance, and means for adjusting the flow of. current through the windings of said throttling devices to cause the same to respond under (litterent predetermined conditions.

7. In a controller for electric motors, in combination, a starting resistance, a plurality of electromagnetically operated switches for gradually removing said resistance from circuit, a plurality of electroresponsivc relay switches, one for each of said resistance switches, each of said relay switches having its operating winding connected in parallel with a portion of said resistance and being adapted to prevent the operation of its corresponding resistance switch while there is an excessive flow of current through the motor, and a variable resistance adapted to be connected in circuit with the winding of each of said relay switches to cause the same to respond under different predetermined conditions.

8. In a controller for electric motors, in combination, a plurality of electromagnetically operated resistance switches, each of said switches waen closed being adapted to close-the circuit of a succeeding switch, a resistance controlled by each of said switches, a plurality of electroresponsive relay switches, one for each of said resistance switches, each of said relay switches having its winding connected in parallel with the resistance controlled by its corresponding resistance switch and being adapted to prevent the closure of its corresponding resistance switch while abnormal conditions exist. each of said resistance switches, when closed, being adapted to short circuit the winding of its corres 'ionding relay switch to render the same inoperative, and means for adjusting said relay switches to respond under d i ii erent predetermined conditions.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

("LARK T. HENDERSON.

IVitnesses FRANK I-l. HUBBARD, h. \V. Firz GERALD. 

